Mechanism for the return movement of heald shafts of a weaving loom

ABSTRACT

Mechanism permitting the easy removal of faulty wovenin weft threads on weaving looms which have come to a stop. The mechanism is provided with a sliding gear wheel on a shaft interposed between the drive of the weaving loom and the gears for driving the heald shafts, said sliding gear wheel, after its disconnection from the drive of the weaving loom permitting return movement of the heald shafts by the action of a pressure air piston actuated by the loom attendant.

tates atent n91 llnite Lev et al.

1 1 Feb. 111, 1975 MECHANIISM FOR THE RETURN MOVEMENT OF HEALD SHAFTS OFA WEAVING LOOM [75] inventors: .laroslav Lev; Karel Kakac, both of Brno,Czechoslovakia [73] Assignee: Vyzkumny a vyvojovy ustav Zavoduvseobecneho strojirenstvi, Brno, Czechoslovakia [22] Filed: Jan. 17,1973 [21] Appl. No; 324,531

[52] 11.5. CI. 139/1 E, 139/56, 139/79, D03c/13/00 [51] Int. Cl. D03d51/00, D03c 5/00 [58] Field of Search 139/1 E, l R, 55, 56, 66 R,139/328, 336, 57, 79-81 [56} References Cited UNITED STATES PATENTS957,724 5/1910 Wyman 139/79 1,883,743 10/1932 Maybach.. 139/1 E2,421,539 6/1947 Clarke 139/1 E 2,639,732 5/1953 Moessinger 139/1 E3,095,015 '6/1963 Cuiengnet 139/1 E 3,237,648 3/1966 Grisay 139/1 EFOREIGN PATENTS OR APPLICATIONS 427,915 5/1935 Great Britain 1. 139/791,015,605 8/1952 France 139/57 464,722 4/1937 Great Britain..... 139/336474,669 11/1937 Great Britain 1 139/56 447,700 5/1936 Great Britain139/66 R 386,174 1/1933 Great Britain 139/1 E Primary Examiner-lames Kee(Chi [57] ABSTRACT Mechanism permitting the easy removal of faultywovenin weft threads on weaving looms which have come to a stop. Themechanism is provided with a sliding gear wheel on a shaft interposedbetween the drive of the weaving loom and the gears for driving theheald shafts, said sliding gear wheel, after its disconnection from thedrive of the weaving loom permitting return movement of the heald shaftsby the action of a pressure air piston actuated by the loom attendant.

3 Claims, 3 Drawing Figures PATENTED FEB] 1 i575 SHEET 2 BF 2 FIG. 3

MECHANHSM FOR THE RETURN MOVEMENT OF HEALID SHAFTS OF A WEAVIING LOOMBACKGROUND OF THE INVENTION The invention relates to a mechanismenabling a return movement of said heald shafts, required for faultywoven in weft treads; the mechanism is particularly advantageous for usewith weaving looms with pressure air control.

In the course of weaving, different faults occur in the produced fabric;some of these faults cause the stopping of the weaving loom. Thisenables the attendant to become aware of the fault, and to care for itsremoval. Faults caused by a wrong weaving in of weft threads are removedby subsequent removal of weft threads form the fabric. This removal can,for instance, be executed by turning the drive of the weaving loom inthe opposite direction; this. however, is not suitable for some types oflooms, for instance for looms provided with arrangements for measuringthe length of the weft thread.

In any case, the removal of weft threads by manually turning the loom istedious and laborious. Different servo-mechanisms for this purpose aretherefore provided, particularly with drives by electric motors, whichare so made that for one impulse of its control by the attendant amovement of the harness corresponding to one revolution of the loom isaccomplished.

A drawback of this solution is the relatively high complexity andpossibility of a failure of the electric motor of the servomechanism dueto possible overload- SUMMARY OF THE INVENTION It is an object of thisinvention to eliminate, or at least mitigate, these drawbacks byintroducing between the drive of the weaving loom and the means fordriving the shafts of healds a sliding gear, provided on both faces withclutches for alternate coupling with a shaft and with a core of afree-wheel coupling. The rim of the coupling has a gear with which arack is in engagement, such rack being connected with the piston of anair cylinder and provided with a stop extension cooperating withresepctive end steps at the opposite ends of its reciprocation.

An advantage of the arrangement according to this invention is itssimpicity with respect to known arrangements, and the easy and reliablecontrol of such arrangement, by actuation of a two arm lever and thepressing of a control push button or pedal of a valve.

DESCRIPTION OF THE DRAWING An examplary embodiment of the object of thisinvention is indicated in the attached drawing, wherein,

FIG. 1 is a schematic elevation partly in section of the entirearrangement;

FIG. 2 is a schematic top view of the arrangement of FIG. 1; and

FIG. 3 is a schematic view in elevation, taken from the line 3 3 of FIG.2 of the mechanism driving the heald shafts of the loom.

DESCRIPTION OF PREFERRED EMBODIMENT A shaft 2 is shown rotatablysupported in a frame I of a weaving loom. A driving gear 3 is fixed toshaft 2, gear 3 meshing with a driving gear (not shown) connected to thedrive of the weaving loom. A sliding gear 4 having teeth 5 is freelyrotatably and axially shiftably supported upon the shaft 2, the slidinggear 4 having a prolonged hub 6. A circumferential groove 7 is providedon this prolonged hub 6, one end of a two-arm lever 8, supported on apivot shaft 9, fixed on the frame 1 of the loom, being disposed insliding arrangement in said groove 7.

The other end of the two arm lever 8 terminates in a handle 10. Thesliding gear 4 has in its sides extensions 11 and 12 respectively,extension 1! being on a face of the sliding gear 4 proper, the extension12 being on the face of the prolonged hub 6. Each of these extensions IIand 12 forms one part of two respective claw clutches. The second partof one claw clutch forms a recess 13, provided in the collar 14 of theshaft 2. A recess 15 is provided in the face of the core 16 of afree-wheel coupling or over-running clutch 17; core 16, which is freelyrotatably supported on the shaft 2, forms the second part of the secondclaw clutch. The core 16 has on its surface a set of recesses 18 housingrollers 19 for engagement with the rim 20 of the freewheel coupling 17.The rim 20 has on its external circumference a gear 21, engaging with arack gear 22. A piston rod 23 is fixed to the rack 22, the piston 24affixed to rod 23 being slidable in an air cylinder 25 fixed on theframe 1 of the weaving loom. A coil compression or return spring 26 isprovided in cylinder 25 in order constantly to urge the piston 24 to theleft (FIG. 2).

The sliding gear 4 is in constant engagement with a gear 27 which,together with another gear 28, is fixed on a shaft 29 which is rotatablysupported on the frame ll of the weaving loom. The gear 28 meshes with afurther gear 30, fixed on another shaft 31, which is also rotatablysupported on the frame 1. A set of earns 32 for the control of the healdshaft is fixed on the shaft 31.

A stop extension or dog 33 on the rack 22 is adapted for engagement withtwo spaced end stops 34 and 35 on the frame 1 to limit the length ofstroke of the piston 24 in the air cylinder 25.

In FIG. 3 there are shown heald shafts 36 and 36 which are slidinglymounted on the frame I of the loom. Pull rods are attached to the healdshaft 36 being designated 37 and 38 respectively. Such pull rods in turnrigidly connected to double-arm levers 39 and 40, as shown. Thedouble-arm levers 39 40 are pivotally mounted upon fixed pivot pins 4iand 42 respectively, which are connected to the frame 1 of the loom. Theopposite end of the double-arm lever 39 is pivotally connected to a link43 which is connected to a cam follower roller 44 which coacts with thecam 32. Extending from the cam follower roller 44 is a bent link 46which extends to the second, upstanding arm of the double-arm lever 40.It will be apparent that as the shaft 31 rotates, the cam 32 rotatestherewith, thereby causing the cam follower roller 44 and the links 43and 46 connected therewith to reciprocate and thus to oscillate therespective double-arm levers 39 and 40. This causes the heald shaft 36,for example, to rise while the heald shaft 36' is descending, and viceversa.

The disclosed mechanism operates as follows:

In the course of weaving, the required power for the control of theheald shafts is transmitted via a driving gear (not shown) of theweaving loom to the transmission gear 3 (FIG. 2) and therfrom by theshaft 2 via a first claw clutch made up of the recess l3 and theextension ll, to the sliding gear 4 the extension ll of which engagesthe collar 14 of the shaft 2. The free end of the two arm lever 8opposite the handle is thereby in the dash line position ll. Therotating motion of the sliding gear 4 is further transmitted to thecounter gear 27 which rotates together with the gear 28. The rotation ofthe gear 28 is transmitted via a further gear 30 and the shaft 31 to aset of cams 32 which control the heald shafts (not shown).

lf due to some fault in the course of weaving-in the weft thread theweaving loom has been stopped and one or more recently woven-in weftthreads have to be removed from the fabric, the attendant sets the twoarm lever 8 by means of the handle 10 into the solid line position I.The second end of the two arm lever 8 engaging into the circumferentialgroove 7 shifts the sliding gear 4 into its second extreme position onthe shaft 2, whereby the extension 11 of the claw clutch is disengagedfrom the recess 13 in the collar 14 and the extension 12 on the face ofthe hub 6 of the sliding gear 4 comes into engagement with the recess 15in the core of the free-wheel coupling 17. The sliding gear 4 remainseven after this shifting in constant driving engagement with the countergear 27 and, by way of it, through the further gears 28 and 30, with theset of cams 32.

After setting of the two arm lever 8 into position I, the attendantpresses the push button or the pedal of a three-way valve (not shown) ofcommon design interposed in the pressure air circuit of the loom. Thepressure air passes via a tubing (not shown) to the left end of the aircylinder above its piston 24. A movement of the piston 24 to the rightis caused by the action of this pressure air, thus compressing thereturn spring 26 and simultaneously shifting the piston rod 23 with therack 22 from its left extreme position into the other right, one. Thestop dog 33 of the rack 22 then rests against the end stop 35, limitingthe length of the stroke of the piston 24. In the course of an axialmovement of the rack 22, to the right (FIGS. 1 and 2), the rim 20 of thefree-wheel coupling 12 is turned clockwise (FIG. 1). In the course ofthe first portion of such rotation of the rim 20, the rollers 19 arecaused to leave to a certain extent the system of recesses 18 of thecore 16 to be clamped between the internal circumference of the rim 20and the core 16 of the free wheel coupling 17. The rollers 19 transmitthereafter in the following phase of such rotation of the rim 20 thetorque from the rim 20 to the core 16. By way of the claw clutch formedby the recess 15 and the extension 12, the rotating motion of the core16 is transmitted further to the sliding gear 4 and therefrom tothe;'counter-gear 27 and through the other gears 28 and 30 to the set ofcams 32 controlling the heald shafts (not shown).

The drive by the rack 22 is oriented so as to cause a direction ofrotation of the set ofcams 32 opposite to direction in which they rotateduring normal weaving. The location and distance betweenend stops 34 and35 must be adjusted so that the piston 24 causes a return movement ofthe heald shafts corresponding to one turn or cycle of the weaving loom.After the described return turning of the set of cams 32, the recentlywoven-in weft thread can be removed from the fabric.

The release of the above-described push button or pedal (not shown)enables thethree-way valve to release the pressure air from the aircylinder 25 by the action of the return spring 26 on the'piston rod 23and thus a return of the rack 22 toward its original left hard terminalposition until the stop dog 33 strikes the second end stop 34. Thereturn movement of the rack 22 is transmitted solely to the rim 20, theturning of which causes a return of the rollers 19 into the system ofrecesses 18 in the core 16 of the free-wheel coupling 17, thus releasingthe free-wheel coupling 17.

The mechanism is thus prepared for a repeated operation; after a newpressing of the push-button or pedal, another weft thread can beremoved.

After the removal of the required number of weft threads had beenaccomplished, the attendant sets the two arm lever 8 into its originaldash line position, that is into position ll according to FIG. 2,whereby the extension 12 is removed from engagement with the recess 15of the core 16 of the freewheel coupling 17, and the second extension 11enters the recess 13 of the collar 14 of the shaft 2. The mechanism isthus again in condition to transmit the torque from the drive of theweaving loom to the heald shafts.

The invention can be applied as part of a weaving loom if an easyremoval of faulty weft threads is required. The mechanism of theinvention is particularly useful in jet weaving looms, wherein the weftthreads are inserted into the fabric in measured separate lengths.

Although the invention is illustrated and described with reference toone preferred embodiment thereof, it is to be expressly understood thatit is in no way limited to the disclosure of such a preferredembodiment, but is capable of numerous modifications within the scope ofthe appended claims.

What is claimed is:

' l. A mechanism for driving the heald shafts of a weaving loom in therearward direction, which is the reverse of their weaving direction, inorder to permit the removal of woven in weft-threads, the loom havingheald shafts and means for driving the heald shafts in the forwardweaving direction comprising a drive shaft rotatably supported on theframe of the weaving loom, said drive shaft freely slidably androtatably supporting a slidable gear and the means for driving the healdshafts, an over-running clutch having a driving and a driver part, andmeans for selectively connecting and disconnecting such driving anddriver parts, second and third clutches for alternately coupling thegear with its supporting drive shaft and with the driving part of theover-running clutch, and means for selectively driving the driving partof the over running clutch in cycles in each of which the cam by whichthe heald shafts are turned is rotated in said rearward directionthrough an angle equalling the degree of turning of the cam of the healdshafts in the opposite direction in one cycle of the weaving operationof the loom.

2. A mechanims according to claim 1 wherein the means for driving thedriving part of the over-running clutch comprises a rack gear, apressure fluid receiving cylinder having a piston with a piston rod, thepiston rod being connected to the rack gear, and comprising a stop dogon the piston rod and spaced end stops for the dog on the frame of theweaving loom, said, rack gear meshing with a further gear, said furthergear being affixed to the driving part of the over-running clutch.

3. A mechanism according to claim 1, wherein said second and thirdclutches are toothed clutches each having one part thereof disposed on arespective one of the opposite sides of the slidable gear, the otherpart of each second and third clutch being a part which matingly engagesa respective formation on the supporting shaft and drive part of theover-running clutch.

1. A mechanism for driving the heald shafts of a weaving loom in therearward direction, which is the reverse of their weaving direction, inorder to permit the removal of woven in weftthreads, the loom havingheald shafts and means for driving the heald shafts in the forwardweaving direction comprising a drive shaft rotatably supported on theframe of the weaving loom, said drive shaft freely slidably androtatably supporting a slidable gear and the means for driving the healdshafts, an over-running clutch having a driving and a driver part, andmeans for selectively connecting and disconnecting such driving anddriver parts, second and third clutches for alternately coupling thegear with its supporting drive shaft and with the driving part of theover-running clutch, and means for selectively driving the driving partof the over running clutch in cycles in each of which the cam by whichthe heald shafts are turned is rotated in said rearward directionthrough an angle equalling the degree of turning of the cam of the healdshafts in the opposite direction in one cycle of the weaving operationof the loom.
 2. A mechanims according to claim 1 wherein the means fordriving the driving part of the over-running clutch comprises a rackgear, a pressure fluid receiving cylinder having a piston with a pistonrod, the piston rod being connected to the rack gear, and comprising astop dog on the piston rod and spaced end stops for the dog on the frameof the weaving loom, said, rack gear meshing with a further gear, saidfurther gear being affixed to the driving part of the over-runningclutch.
 3. A mechanism according to claim 1, wherein said second andthird clutches are toothed clutches each having one part thereofdisposed on a respective one of the opposite sides of the slidable gear,the other part of each second and third clutch being a part whichmatingly engages a respective formation on the supporting shaft anddrive part of the over-running clutch.